SHIP MATERIALS

1.3.3 Local supporting members Part 3 Chapter 3 Section 2 The net cross-sectional area, the moment of inertia about the y-axis and the associated neutral axis position shall be determined applying a corrosion magnitude of 0.5 tc deducted from the surface of the profile cross- section. Rules for classification: Ships — DNVGL-RU-SHIP Pt.3 Ch.3. Edition January 2017 Page 26 Structural design principles DNV GL AS

SECTION 3 CORROSION ADDITIONS Part 3 Chapter 3 Section 3 Symbols For symbols not defined in this section, see Ch.1 Sec.4. tc = corrosion addition, in mm tc1, tc2 = corrosion addition, in mm, on each of the two sides of the considered structural member, as tres defined in Table 1 = reserve thickness, taken as 0.5 mm, also to be applied in non corrosive environment and for stainless steel and aluminium to account for possible thickness reductions, e.g. wear and tear, grinding or under tolerance thickness. 1 General 1.1 Application The corrosion additions given in these rules are applicable to carbon-manganese steels, stainless steels, stainless clad steels and aluminium alloys. 1.2 Corrosion addition determination 1.2.1 The total corrosion addition, tc in mm, for both sides of the structural member is obtained by the following formula: 1.2.2 For an internal member within a given compartment, the total corrosion addition, tc is obtained from the following formula: where tc1 is the value specified in Table 1 for one side exposure to that compartment. 1.2.3 The total corrosion addition, tc in mm, for compartment boundaries and internal members made from stainless steel, or aluminium shall be taken as: 1.2.4 In case of stainless clad steel, the corrosion additions, tc1, for the carbon steel side and tc2, for the stainless steel side shall respectively be taken as: tc1 = as specified for the corresponding compartment in Table 1 tc2 = 0 1.2.5 Maximum value of corrosion addition The total corrosion addition, tc, need not to be taken more than: where tcmax shall be rounded to the closest half millimetre. Rules for classification: Ships — DNVGL-RU-SHIP Pt.3 Ch.3. Edition January 2017 Page 27 Structural design principles DNV GL AS

1.2.6 Stiffener Part 3 Chapter 3 Section 3 The corrosion addition of a stiffener is determined according to the location of its connection to the attached plating. The maximum corrosion margin given in [1.2.5] applies and may give different corrosion addition for web and flange. 1.2.7 When an elementary plate panel or a stiffener are affected by more than one value of corrosion addition, the largest value shall be applied. Table 1 Corrosion addition for one side of a structural member Compartment type Structural member tc1 or tc2 1.0 Tanks for cargo oil and liquid chemicals All members Dry bulk, container and general cargo holds 2.5 Lower part 1) for vessels with Grab(3- X) notation 1.0 0.5 Lower part2) for other vessels 0.5 1.0 Other members 0.5 1.0 External surfaces All members 0.0 Ballast water tank All members 0.5 Tanks for fresh water, fuel oil, lube oil, RSW, mud4) All members 0.0 Tanks for brine, urea, bilge tank, drain storage, chain locker All members 0.0 Accommodation spaces All members Void, dry spaces and compartment types not mentioned Upper surface of decks or bottom plate above3) of the compartment 5) Elsewhere Stainless steel and aluminium (independent of All members compartment type) 1) Lower part includes the bottom of hold and other structure within a height of 3.0 m above the bottom of hold, e.g. inner bottom. The bottom of hold is defined as the lowest horizontal boundaries of the hold. 2) Lower part includes the bottom of hold and other structure within a height of 1.5 m above the bottom of hold, e.g. inner bottom. The bottom of hold is defined as the lowest horizontal boundaries of the hold. 3) Applicable for the spaces containing membrane or independent cargo tanks of gas carriers. But membrane and independent tank themselves are not covered by this part of the rules, see Pt.5 Ch.7. 4) Applicable also for cargo tanks only intended to carry fresh water, fuel oil, lube oil, RSW or mud. 5) Inclusive upper surface of horizontal stringers in double hull and double bulkhead constructions. Rules for classification: Ships — DNVGL-RU-SHIP Pt.3 Ch.3. Edition January 2017 Page 28 Structural design principles DNV GL AS

SECTION 4 CORROSION PROTECTION Part 3 Chapter 3 Section 4 1 General 1.1 Application 1.1.1 Tanks and holds Tanks and holds that are exposed to a corrosive environment shall have an efficient corrosion prevention system. For vessels following PSPC requirements, the dedicated seawater ballast tanks shall have an efficient corrosion prevention system in accordance with SOLAS Chapter II-1/3-2 and IMO Resolution MSC.215(82): Performance Standard for Protective Coatings (PSPC) for Dedicated Seawater Ballast Tanks in All Types of Ships and Double-Side Skin Spaces of Bulk Carriers and cargo oil tanks of crude oil carriers shall have an efficient corrosion prevention in accordance with SOLAS Chapter II-1/3-11 and IMO Resolution MSC.288(87) or MSC.289(87). 1.1.2 Narrow spaces Narrow spaces shall generally be protected by an efficient protective product, particularly at the ends of the ship where inspections and maintenance are not easily practicable due to their inaccessibility. 1.2 Paint containing aluminium Paint containing aluminium, when used in cargo tanks, shall comply with CSR Pt.2 Ch.2 Sec.2 [1.3]. 2 Sacrificial anodes 2.1 Attachment of anodes to the hull 2.1.1 All anodes shall be attached to the structure in such a way that they remain securely fastened even when it is wasted. The following methods are acceptable: a) steel core connected to the structure by continuous fillet welds b) attachment to separate supports by bolting, provided a minimum of two bolts with lock nuts are used. However, other mechanical means of clamping may be accepted. 2.1.2 Anodes shall be attached to stiffeners or aligned in way of stiffeners on plane bulkhead plating, but they shall not be attached to the shell. The two ends shall not be attached to separate members which are capable of relative movement. 2.1.3 Where cores or supports are welded to local supporting members or primary supporting members, they shall be kept clear of end supports, toes of brackets and similar stress raisers. Where they are welded to asymmetrical members, the welding shall be at least 25 mm away from the edge of the web. In the case of stiffeners or girders with symmetrical face plates, the connection may be made to the web or to the centreline of the face plate, but well clear of the free edges. 2.1.4 Cargo tanks Cathodic protection systems, if fitted in tanks for cargo with flash point below 60°C, and adjacent tanks, shall comply with the requirements specified in CSR Pt.2 Ch.2 Sec.2 [1]. Rules for classification: Ships — DNVGL-RU-SHIP Pt.3 Ch.3. Edition January 2017 Page 29 Structural design principles DNV GL AS

SECTION 5 STRUCTURAL ARRANGEMENT Part 3 Chapter 3 Section 5 Symbols For symbols not defined in this section, see Ch.1 Sec.4. 1 Application 1.1 Introduction If not specified otherwise, the requirements of this section apply to the hull structure, superstructures and deckhouses for ships with length L ≥ 65 m. Alternative structural layout to what is specified in this section may be considered based on direct calculations reflecting the actual design. 2 General principles 2.1 Structural continuity 2.1.1 General Attention shall be paid to the structural continuity, in particular in the following areas: — in way of changes in the framing system — at end connections of primary supporting members or stiffeners — in way of the transition zones between midship area and fore part, aft part and machinery space — in way of side and end bulkheads of superstructures. At the termination of a structural member, structural continuity shall be maintained by the fitting of effective supporting structure. Between the midship region and the end regions there shall be a gradual transition in plate thickness for bottom, shell and strength deck plating. 2.1.2 Longitudinal members Longitudinal members shall be arranged in such a way that continuity of strength is maintained. Longitudinal members contributing to the hull girder longitudinal strength shall extend continuously as far as practicable within 0.8 L amidships for vessels with L < 150 m and within 0.5 L amidships for ships with L < 90 m. Linear interpolation is applicable for vessels with length between 90 m and 150 m. Structural continuity shall be ensured in way of end terminations. For longitudinal bulkheads or deep girders, large transition brackets, fitted in line with the longitudinal member are a possible means to achieve such structural continuity. 2.2 Longitudinal stiffeners 2.2.1 Within 0.8 L for vessels with L > 150m , in the area below 0.15 D above the bottom and the area above 0.15 D below strength deck, longitudinal stiffening arrangement shall in general be applied. For ships with length L < 90 m longitudinal stiffening arrangement shall in general be applied within 0.5 L. Linear interpolation is applicable for vessels with length between 90 m and 150 m. 2.2.2 Where stiffeners are terminated in way of large openings, foundations and partial girders, compensation shall be arranged to provide structural continuity in way of the end connection. 2.2.3 When the bottom or inner bottom is longitudinally stiffened, the longitudinals shall in general be continuous through transverse members. For ships with length L < 65 m or other ships with low hull girder Rules for classification: Ships — DNVGL-RU-SHIP Pt.3 Ch.3. Edition January 2017 Page 30 Structural design principles DNV GL AS

stresses and not considered prone to fatigue the longitudinals may be non-continuous and welded against the Part 3 Chapter 3 Section 5 floors. 2.2.4 Deck longitudinals shall in general be continuous at transverse members as given in [2.2.1]. For vessels with more than two decks above 0.7 D and σhg ≤ 0.5 · σhg-perm for the deck plating in question, the longitudinals may be terminated at transverse members. σhg = hull girder longitudinal stress, in N/mm2, due to bending moments as defined in Ch.5 Sec.3 [2.1] for ships without large deck openings σhg-perm = permissible hull girder stress, in N/mm2, as given in Ch.5 Sec.3 [2.1] for ships without large deck openings. For ships with length L < 65 m or other ships with low hull girder stresses and not considered prone to fatigue the longitudinals may be non-continuous and welded against the transverse members/ bulkheads. In case of deck longitudinals subjected to high tensile hull girder stresses are made non-continous, welding requirements are given in Ch.13 Sec.1 [2.4.5]. 2.3 Transverse stiffeners Transverse and vertical stiffeners shall be continuous through stringers/girders, if provided, or fitted with bracket end connections. 2.4 Plating Where plates with different thicknesses are joined, a transition plate shall be added if the difference in the as-built plate thickness exceed 50% of larger plate thickness in the load carrying direction. This also applies to the strengthening by local inserts, e.g. insert plates in double bottom girders, floors and inner bottom. For welding of plates with different thicknesses, see Ch.13 Sec.1 [3.2]. 2.5 Sheer strake 2.5.1 Sheer strakes shall have breadths in m not less than 0.8 + L/200, measured vertically, but need not be greater than 1.8 m. 2.5.2 The thickness of sheer strake shall be increased by 30% on each side of a superstructure end bulkhead located within 0.5 L amidships if the superstructure deck is a partial strength deck. 2.5.3 If the sheer strake is rounded by cold forming, its radius shall be in accordance with Sec.1 [2.7]. When it is intended to use hot forming for rounding of the sheer strake, all details of the forming and heat treatment procedures shall be submitted to the Society for approval. Appropriate heat treatment subsequent to the forming operation will normally be required. Where the rounded sheer strake transforms into a square corner towards the ends of the vessel, line flame heating may be accepted to bend the sheer strake. 2.6 Stringer plate 2.6.1 Stringer plates shall have breadths not less than 0.8 + L/200 m, measured parallel to the deck, but need not be greater than 1.8 m. 2.6.2 Rounded stringer plates, where adopted, shall comply with the requirements in [2.5.3]. Rules for classification: Ships — DNVGL-RU-SHIP Pt.3 Ch.3. Edition January 2017 Page 31 Structural design principles DNV GL AS

2.7 Connection of deckhouses and superstructures Part 3 Chapter 3 Section 5 Connection of deckhouses and superstructures to the strength deck and hatch coamings shall be designed such that loads are transmitted into the under deck supporting structure. 3 Bottom structure 3.1 General 3.1.1 Variation in height of double bottom Any variation in the height of the double bottom shall generally be made gradually and over an adequate length; the knuckles of inner bottom plating shall be located in way of plate floors or girders. Where such arrangement is not possible, suitable structures such as partial girders, brackets or carlings fitted across the knuckle shall be arranged. 3.1.2 Connection between inner hull and inner bottom plating Connection between the inner hull plating and the inner bottom plating shall be designed such that stress concentration is minimized. The connection of inner hull plating or hopper plating with inner bottom shall be effectively supported, e.g. by a longitudinal girder or gusset plates. 3.1.3 Striking plate Striking plates of adequate thickness or other equivalent arrangements shall be provided under sounding pipes to prevent the sounding rod from damaging the plating. 3.1.4 Duct keel Where a duct keel is arranged, the centre girder may be replaced by two girders spaced no more than 3 m apart. Spacing wider than 3 m will be specially considered. 3.1.5 Keel plating Keel plating shall extend over the bottom for the full length of the ship. The width of the keel strake, in m, shall not be less than 0.8 + L/200, but need not be taken greater than 2.3 m. 3.2 Girders 3.2.1 In double bottoms with transverse stiffening the longitudinal girders shall be stiffened at every transverse frame. 3.2.2 Double bottom girders shall be arranged in line with longitudinal bulkheads arranged from the inner bottom and above. 3.2.3 When fitted, the centre girder shall extend continuously within the full length of the ship, as far as practicable. 3.3 Floors 3.3.1 Plate floors shall be fitted below bulkheads, in way of double bottom structures. 3.3.2 Floors shall be provided with web stiffeners in way of longitudinal stiffeners. Where the web stiffeners are not welded to the longitudinal stiffeners, design standard as given in the Society's document DNVGL- CG-0129 Fatigue assessment of ship structure, may be applied. Rules for classification: Ships — DNVGL-RU-SHIP Pt.3 Ch.3. Edition January 2017 Page 32 Structural design principles DNV GL AS

3.4 Docking Part 3 Chapter 3 Section 5 3.4.1 Docking of the vessel shall be evaluated and considered at the design stage by the designer. The bottom structure shall withstand the forces imposed by dry docking the ship. 3.4.2 Docking brackets connecting the centreline girder and margin girder to the bottom plating, shall be connected to the adjacent bottom longitudinals. Docking brackets shall be fitted between floors. Alternative arrangements require special consideration of local buckling strength of centre girder and local strength of bottom longitudinal in way of docking block. 3.5 Ships touching ground during loading and discharging The bottom structure of a ship which is expected to frequently touch the ground during loading and discharging will be specially considered. 4 Aft peak 4.1 Application The area of application is aft of the aft peak bulkhead and below bulkhead deck. 4.2 Structural arrangement 4.2.1 Minimum thickness requirement The net thickness of the aft peak bulkhead plating in way of the stern tube penetration shall be at least 1.6 times the required thickness for the bulkhead plating itself. 4.2.2 Floors Floors shall be fitted at every frame in the aft peak and extended to a height at least above the stern tube. Where floors do not extend to flats or decks, they shall be stiffened by flanges at their upper end. Heavy plate floors shall be fitted in way of the aft face of the rudder horn and in line with the webs in the rudder horn. They may be required to be carried up to the first deck or flat. In this area, cut outs, scallops or other openings shall be kept to a minimum. 4.2.3 Platforms and stringers Platforms and side girders within the peak shall be arranged in line with those located in the area immediately forward. Where this arrangement is not possible due to the shape of the hull and access needs, structural continuity between the peak and the structures of the area immediately forward shall be ensured by adopting wide tapering brackets. Where the aft peak is adjacent to a machinery space with longitudinal framing, the side girders in the aft peak shall be fitted with tapering brackets. Where the depth from the peak tank top to the weather deck is greater than 2.6 m and the side is transversely framed, one or more side girders shall be fitted, preferably in line with similar structures existing forward. 4.2.4 Longitudinal bulkheads A longitudinal non-tight bulkhead shall be fitted on the centreline of the ship, in general in the upper part of the peak, and stiffened at each frame spacing. Rules for classification: Ships — DNVGL-RU-SHIP Pt.3 Ch.3. Edition January 2017 Page 33 Structural design principles DNV GL AS

Where either the stern overhang is very large or when the breadth of the tank is greater than 2/3 of the Part 3 Chapter 3 Section 5 moulded breadth of the ship, additional longitudinal wash bulkheads may be required. 4.2.5 Stern tube The stern tube shall be supported by the floor plates or, when the ship’s shape is too narrow, to be stiffened by internal rings. Where no sole piece is fitted, the internal rings may be dispensed with. 4.2.6 Alternative design verification The spacing and arrangement requirements, defined in [4.2.2], [4.2.3] and [4.2.4], may be increased, if verification by means of grillage analysis or FE analysis is performed. The acceptance criteria to be applied for grillage analysis are defined in Ch.6 Sec.6 [2]. A FE analysis shall be performed in accordance with the requirements in Ch.7. 4.3 Stiffening of floors and girders in aft peak 4.3.1 The height of stiffeners, in mm, on the floors and girders shall satisfy: hstf ≥ 80 ℓstf for flat bar stiffeners hstf ≥ 70 ℓstf for bulb profiles and flanged stiffeners where: ℓstf = length of stiffener, in m, as shown in Figure 1. For this purpose the length need not be taken greater than 5 m. 4.3.2 Stiffeners on the floors and girders in aft peak ballast or fresh water tanks above the propeller shall be arranged with brackets. This applies for stiffeners located in an area extending longitudinally between the forward edge of the rudder and the aft end of the propeller boss and transversely within the diameter of the propeller. End brackets shall be provided as follows: — brackets shall be fitted at the lower and upper ends when ℓstf-t exceeds 4 m — brackets shall be fitted at the lower end when ℓstf-t exceeds 2.5 m. where: ℓstf-t = total length of stiffener, in m, as shown in Figure 1. Rules for classification: Ships — DNVGL-RU-SHIP Pt.3 Ch.3. Edition January 2017 Page 34 Structural design principles DNV GL AS

Figure 1 Stiffening of floors and girders in the aft peak tank Part 3 Chapter 3 Section 5 5 Engine room 5.1 Bottom structure 5.1.1 Application The requirements in [5.1.3] to [5.1.8] apply unless verification by means of direct analysis. 5.1.2 Double bottom height The double bottom height at the centreline shall not be less than the value defined in Ch.2 Sec.3 [2.3]. This depth may need to be considerably increased in relation to the type and depth of main machinery seatings. The above height shall be increased where the engine room is very large and where there is a considerable variation in draught between light ballast and full load conditions. Where the double bottom height differs from that in adjacent spaces, structural continuity of longitudinal members shall be provided by sloping the inner bottom over an adequate longitudinal extent. The knuckles in the sloped inner bottom shall be located in way of floors. Lesser double bottom height may be accepted in local areas provided that the overall strength of the double bottom structure is not thereby impaired. 5.1.3 Centreline girder The double bottom shall be arranged with a centreline girder or side girders adjacent to centreline giving sufficient support for docking loads. Openings for manholes are only permitted where absolutely necessary for double bottom access and maintenance, local strengthening may be required. 5.1.4 Side bottom girders The number of side bottom girders shall be increased, with respect to the adjacent areas, to provide adequate rigidity of the structure. The side bottom girders in a longitudinal stiffened double bottom, shall be a continuation of any bottom longitudinals in the areas adjacent to the engine room and are generally to have a spacing not greater than 3 times that of longitudinals and in no case greater than 3 m. 5.1.5 Girders in way of machinery seatings Under the main engine, girders extending from the bottom to the top plate of the engine seating, shall be fitted. The height of the girders shall not be less than that of the floors. Rules for classification: Ships — DNVGL-RU-SHIP Pt.3 Ch.3. Edition January 2017 Page 35 Structural design principles DNV GL AS

Guidance note: Part 3 Chapter 3 Section 5 Side girders under foundation girders shall be extended into the adjacent spaces and to be connected to the bottom structure. This extension abaft and forward of the engine room bulkheads shall be two to four frame spacings, as found practicable. ---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e--- 5.1.6 Floors in longitudinally stiffened double bottom Where the double bottom is longitudinally stiffened, plate floors shall be fitted at every frame under the main engine and thrust bearing. Forward and aft of the engine and bearing seatings, the floors may be fitted with greater spacing if the double bottom is supported by effective longitudinal girders or partial longitudinal bulkheads. 5.1.7 Floors in transversely stiffened double bottom Where the double bottom in the engine room is transversely stiffened, floors shall be arranged at every frame. 5.1.8 Manholes The number and size of manholes in floors located in way of seatings and adjacent areas shall be kept to the minimum necessary for double bottom access and maintenance. 5.2 Side structure In the engine room, web frames shall be spaced not more than 5 times the frame spacing apart. The web frames shall extend to the uppermost continuous deck. Greater web frame spacing may be accepted provided that partial ship structural analysis in accordance with Ch.7 Sec.3 is carried out. For two-stroke engines, web frames shall generally be fitted at the forward and aft ends of the engine. The web frames shall be evenly distributed along the length of the engine. 6 Fore peak 6.1 Application The area of application is forward of collision bulkhead and below bulkhead deck. 6.2 Floors and bottom girders 6.2.1 Floors The minimum depth of the floor at the centreline shall not be less than the required depth of the double bottom, see Ch.2 Sec.3 [2.3]. 6.2.2 Bottom girders A supporting structure shall be provided at the centreline either by extending the centreline girder to the stem or by providing a deep girder or centreline bulkhead. In areas where the hull shape is very narrow, alternative arrangement, e.g. without centreline girder and with web fitted at every frame, may be accepted. Where a centreline girder is fitted, the minimum depth and thickness shall not be less than that required for the depth of the double bottom in the neighbouring cargo hold region, and the upper edge shall be stiffened. Rules for classification: Ships — DNVGL-RU-SHIP Pt.3 Ch.3. Edition January 2017 Page 36 Structural design principles DNV GL AS

6.3 Wash bulkheads Part 3 Chapter 3 Section 5 Where a centreline wash bulkhead is fitted, the lowest strake shall have thickness not less than required for a centreline girder. Where a longitudinal wash bulkhead supports bottom transverses, the details and arrangements of openings in the bulkhead shall be configured to avoid areas of high stresses in way of the connection of the wash bulkhead with bottom transverses. Rules for classification: Ships — DNVGL-RU-SHIP Pt.3 Ch.3. Edition January 2017 Page 37 Structural design principles DNV GL AS

SECTION 6 DETAIL DESIGN Part 3 Chapter 3 Section 6 Symbols For symbols not defined in this section, see Ch.1 Sec.4. 1 Reinforcement of knuckles 1.1 Local reinforcements 1.1.1 Reinforcements at knuckles a) Knuckles shall in general be stiffened to achieve out-of-plane stiffness by fitting stiffeners or equivalent means in line with the knuckle. b) Whenever a knuckle in a main member, e.g. shell or longitudinal bulkhead, is arranged, stiffening in the form of webs, brackets or profiles shall be connected to support the knuckle. See example of reinforcement at knuckle in Figure 1. c) Where stiffeners intersect the knuckle as shown in Figure 1, effective support shall be provided for the stiffeners in way of the knuckle. d) When the stiffeners of the shell, inner shell or bulkhead intersect a knuckle at a narrow angle, it may be accepted to interrupt the stiffener at the knuckle, provided that proper end support in terms of carling, bracket or equivalent is fitted. Alternative design solution with, e.g. closely spaced carlings fitted across the knuckle between longitudinal members above and below the knuckle may be accepted. e) For longitudinal shallow knuckles, i.e. angle less than 10 degrees, closely spaced carlings shall be fitted across the knuckle, between longitudinal members above and below the knuckle. Carlings or other types of reinforcement need not be fitted in way of shallow knuckles that are not subject to high lateral loads and/or high in-plane loads across the knuckle, such as deck camber knuckles. f) Generally, the distance between the knuckle and the support stiffening in line with the knuckle shall not be greater than 50 mm within 0.6 L. For shallow knuckles, i.e. angles less than 10 degrees, the distance of 75 mm is acceptable. Alternative arrangements can be considered based on fatigue analysis in accordance with Ch.9. g) When a stiffener or primary supporting member is knuckled within the length of the span, effective support shall be provided by fitting tripping bracket or equivalent for the support of the face plate, and tripping bracket or equivalent for supporting the knuckled web section, see Figure 2. Rules for classification: Ships — DNVGL-RU-SHIP Pt.3 Ch.3. Edition January 2017 Page 38 Structural design principles DNV GL AS

Part 3 Chapter 3 Section 6 Figure 1 Reinforcement at knuckle Figure 2 Support arrangement for knuckled stringer Page 39 Rules for classification: Ships — DNVGL-RU-SHIP Pt.3 Ch.3. Edition January 2017 Structural design principles DNV GL AS

1.1.2 Knuckle support at integral bracket Part 3 Chapter 3 Section 6 If the flange transition between the stiffener and an integral bracket is knuckled, the flange shall be effectively supported in way of the knuckle. Alternatively the flange may be curved with radius, in mm, not less than, see Sec.7 Figure 15: where: b1 = free flange outstand, in mm, as defined in Sec.7 [1.3.4] tf = net thickness, in mm, of flange. Guidance note: Shell stiffeners in the bow flare area, having an integral end bracket, are generally recommended to be tripping supported in way of the end bracket, also when the flange transition has been curved. ---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e--- 2 Stiffeners 2.1 General 2.1.1 Stiffeners in local areas shall in general be connected at their ends. However, in special cases sniped ends may be permitted. Requirements for the various types of connections (bracketed, bracketless or sniped ends) are given in [2.2] to [2.4]. 2.1.2 Where the angle between the web plate of the stiffener and the attached plating is less than 50 deg, a tripping bracket/carling shall be fitted. If the angle, φw, between the web plate of an unsymmetrical stiffener and the attached plating is less than 50 deg, the face plate of the stiffener shall be fitted on the open angle side, see Figure 3. Figure 3 Stiffener on attached plating with an angle less than 50 deg Page 40 Rules for classification: Ships — DNVGL-RU-SHIP Pt.3 Ch.3. Edition January 2017 Structural design principles DNV GL AS

2.2 Bracketed end connections of non-continuous stiffeners Part 3 Chapter 3 Section 6 2.2.1 Where continuity of strength of longitudinal members is provided by brackets, the alignment of the brackets on each side of the primary supporting member shall be ensured, and the scantlings of the brackets shall be such that the combined stiffener/bracket section modulus and effective cross sectional area are not less than those of the member. Guidance note: End brackets for stiffeners may, as indicated in item (a) and (b) of Figure 4, be of overlap type. End brackets of this type, however, shall only be applied at locations where the bending moment capacity required for the bracket is reduced compared to the bending moment capacity of the stiffener, e.g. the upper end bracket of vertical stiffeners. ---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e--- Rules for classification: Ships — DNVGL-RU-SHIP Pt.3 Ch.3. Edition January 2017 Page 41 Structural design principles DNV GL AS

Part 3 Chapter 3 Section 6 Figure 4 End brackets in way of non-continuous stiffeners Page 42 Rules for classification: Ships — DNVGL-RU-SHIP Pt.3 Ch.3. Edition January 2017 Structural design principles DNV GL AS